JPS6325650A - Developer for positive type photoresist - Google Patents

Abstract

PURPOSE:To form a pattern without leaving scum or a thin film after development by adding a prescribed amount of a nonionic surfactant represented by a specified formula to a developer for a positive type photoresist. CONSTITUTION:At least one kind of nonionic surfactant represented by formula I or II is added by 50-5,000ppm to a developer for a positive type photoresist contg. an org. base contg. no metal ion as a principal component. In the formulae I, II, R1 is 5-15C alkyl, each of R2-R4 is H or 1-15C alkyl, and each of n and m is an integer of 5-60. Thus, the power of the developer to penetrate into a fine pattern part is increased and a resist pattern is obtd. without leaving resin, scum or a thin film by the cleaning and dissolving properties.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a developer for positive photoresists. More specifically, the present invention is capable of forming a good pattern without leaving a thin film or scum in the fine parts of a resist pattern after development, and is suitable for improving the resolution of fine through holes. This invention relates to a developer for positive photoresists.

BACKGROUND OF THE INVENTION Conventionally, in the manufacture of semiconductor integrated circuit elements, masks for integrated circuit manufacturing, printed wiring boards, printing plates, etc., when a base substrate is subjected to processing such as etching or diffusion, the substrate? For the purpose of selective protection, a film is formed using a composition sensitive to actinic radiation such as ultraviolet rays, X-rays, and electron beams, so-called radiation-sensitive resist, and then exposed and developed to form an image. This method is widely used.

Among these radiation-sensitive resists, those that are particularly sensitive to ultraviolet rays are generally called photoresists, but there are two types of photoresists: positive and negative types9. It is a type where the exposed part does not dissolve, so there is no dust.
The latter is the opposite type. A typical example of the former positive type photoresist is a combination of an alkali-soluble novolak resin as a binder and a naphthoquinone diazide compound as a photodegrading agent. An alkaline aqueous solution is used as a developer for this naphthoquinone diazide compound-based positive photoresist, but when manufacturing semiconductor devices, semiconductor device products can be obtained by using an alkaline aqueous solution containing metal ions as a developer. Because it has an adverse effect on custom orders, we recommend using a developing solution that does not contain any metal ions, such as tetramethylammonium hydroxide (from IBM Technical Disclosure).
Bulletin) J Volume 3, No. 7, No. 200
9 pages (1970)], Colin (U.S. Patent No.
239,661) and the like are used.

Recently, the integration of semiconductor devices has rapidly progressed, and the control line width is now required to be around 1 μm or even less than 1 μm.

One of the major problems associated with forming images using positive photoresists is that such microscopic... When forming images of particularly fine contact holes in H pattern areas, a type of development [= use] that completely improves wettability by adding a surfactant to the above-mentioned alkaline developer that does not contain metal ions. When developed, scum residue 9 or thin film residue may be generated in the exposed pattern portion to be dissolved. In order to completely avoid such phenomena, it is difficult to form a wide image even if overexposure and overdevelopment are performed. Therefore, all remaining scum and thin films are usually removed by light treatment using oxygen plasma or sputtering, but with these methods, it is difficult to control the oxygen plasma treatment, and the resist The shape may deteriorate or even 1. In pattern parts such as contact holes in the vicinity of αm, the uniformity of oxygen plasma treatment is low, and there are problems such as difficulty in smoothly removing scum.

If the base is processed, such as dry etching, with such scum or thin film remaining,
All undesirable situations may occur, such as insufficient etching or poor dimensional accuracy and etched shape.

Problems to be Solved by the Invention The object of the present invention is to solve all of these problems, and to provide a method suitable for forming a pattern using a positive photoresist consisting of a combination of a naphthoquinonediazide compound and an alkali-soluble novolac resin. In other words, when forming fine patterns around 1 μm or less or forming fine contact holes, it is possible to form good patterns without scum or thin film residue after development processing, and to process with high dimensional accuracy during etching in the subsequent process. Another object of the present invention is to provide a developer for positive photoresists.

Means for Solving the Problems The present inventors have conducted intensive research to develop a developer for positive photoresist having such favorable properties. The inventors have discovered that the objective can be achieved by adding a specific non-ionic surfactant in a predetermined ratio to a positive photoresist developer, and based on this knowledge, the present invention has been accomplished. .

That is, the present invention provides a positive photoresist developer containing an organic base containing no metal ions as a main ingredient, which has the general formula R4 (wherein R1 is an alkyl group having 5 to 15 carbon atoms, R2, R
3 and R4 are each a hydrogen atom or an alkyl group having 1 to 15 carbon atoms, R3 and R4 may be the same or different from each other, and n and m are each 5 to 6.
The present invention provides a positive photoresist developer, characterized in that at least one nonionic surfactant selected from among the nonionic surfactants represented by be.

The present invention will be explained in detail below.

The positive photoresist developer of the present invention, which is based on an organic base that does not contain metal ions, is a developer solution in which only an organic base that does not contain metal ions, which is the main ingredient of the developer, is dissolved in water, and a conventional developer. Includes all additives commonly used in liquids.

As the metal ion-free organic base constituting the main component of the developer, all conventional bases conventionally used in this type of developer can be used as they are. These include, for example, aryl and alkyl amines containing linear, branched or cyclic primary, secondary and tertiary amines, such as 1,3-diaminopropane. Amines such as alkylene diamines, diamines such as 4,4'-diaminodiphenylamine, and bis(dialkylamino)imines have 3 to 5 carbon atoms in the ring skeleton and are selected from nitrogen, oxygen, and sulfur. Heteroatom 1
or a heterocyclic base having two bases, such as pyrrole, pyrrolidine, pyrrolidone, pyridine, morpholyl, pyrazine, piperidine, oxazole, thiazole, or a lower alkyl quaternary ammonium base. Particularly preferred among these are tetramethylammonium hydroxide and trimethyl(2-hydroquinethyl)ammonium hydroxide (choline). Moreover, the above-mentioned organic bases not containing metal ions may be used alone or in combination of two or more.

Additives commonly used in conventional developing solutions of the present invention include wetting agents, stabilizers, and dissolution aids, and are used to improve dissolution selectivity between exposed and non-exposed areas of a positive photoresist film. Examples include cationic surfactants. These may be added alone or in combination of two or more.

The nonionic surfactant added to the developer of the present invention is
It is selected from those represented by the general formulas (I) and (It). Examples of such substances include, but are not limited to, alkylphenol polyethoxylates, dialkylphenol polyethoxylates, naphthylenol polyethoxylates, alkylnaphthylenol polyethoxylates, and dialkylnaphthenol polyethoxylates. do not have. Further, each of these may be used alone or in combination of two or more.

The amount of these nonionic surfactants added is 50 to 5000 ppm to a positive photoresist developer whose main ingredient is an organic base that does not contain metal ions.

It is preferably selected within the range of 100 to 2000 ppm.

If this amount is less than 50 ppm, the wetting effect will be weak and the resolution will be low, while if it exceeds 5000 ppm, the dissolution selectivity between exposed areas and non-exposed areas will be poor, and the resist shape after development will deteriorate. This is not preferable because the desired resist shape cannot be obtained and the residual ratio of non-exposed areas decreases.

The positive photoresist targeted by the developer of the present invention is not particularly limited as long as it is a positive type photoresist in which the exposed areas are dissolved in the alkaline developer and the non-exposed areas are not dissolved. A preferred positive photoresist is one containing an alkali-soluble novolak resin and a naphthoquinonediazide compound as all constituent components.

Effects of the Invention The developer for positive photoresists of the present invention (3) is a developer for positive photoresists, in which a specific non-ionic potting agent with excellent permeability, cleaning properties and solubility is used as a main ingredient of an organic base. By adding it to the developer, it increases the permeability of the developer to the fine pattern area, and due to its washability and solubility, it is thought to be a reaction product of the resin and photodecomposer that are the constituent components of positive photoresist. To obtain a resist pattern that can remove scum and thin film from all over the substrate, without deteriorating the shape or reducing resolution, and without leaving any scum or thin film, even in 1 μm fine pattern parts and contact hole parts. Can be done.

Example Next, the present invention will be explained in more detail with reference to Examples.

Examples 1 to 17 As a developer, 200 to 5000 pp of various nonionic surfactant injection agents shown in the attached table were added to a 2.38 wt% tetramethylammonium hydroxide aqueous solution.
A range of m was prepared with additions as shown in the vestibule.

onto a 4-inch silicon wafer using a spinner.
0FPR-50 is a positive photoresist containing novolac resin and naphthoquinone diazide compound as constituent components.
00 (manufactured by Tokyo Ohka Kogyo Co., Ltd., trade name) to a film thickness of 1.3 μm, and heated at 110°C on a hot plate for 90 minutes.
Prebaked for 0 seconds.

Next, DSW-4800 reduction projection exposure system (GCA M
), and after exposure through a test chart reticle, development was performed using a stationary paddle type developing device.

Regarding the development process, static development was performed for 65 seconds at 23° C. using the developer prepared as described above, followed by rinsing with pure water for 30 seconds, and then drying.

The pattern thus obtained on the wafer was observed, and the results were shown here.

Comparative Example When processed in the same development process as in the example using only a 2.38 wt% tetramethylammonium hydroxide aqueous solution without adding a nonionic surfactant, scum and thin film residue were observed in the fine pattern area. It was done.

Claims (1)

[Scope of Patent Claims] 1. A positive photoresist developer whose main ingredient is an organic base that does not contain metal ions has the general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ and ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ ( In the formula, R_1 is an alkyl group having 5 to 15 carbon atoms, R_2
, R_3 and R_4 each have a hydrogen atom and a carbon number of 1 to 1
5 alkyl group, R_3 and R_4 may be the same or different, and n and m are each an integer of 5 to 60). 50 to 5 of at least one type selected from
A developer for a positive photoresist, characterized in that the developer is added at a rate of 0,000 ppm.